(1) Field of the Invention
The present invention pertains to an apparatus that adjusts the positions of a pair of guide rails of a conveyor. In particular, the present invention pertains to an apparatus that supports a pair of bottle air conveyor guide rails and is operable to simultaneously adjust a lateral spacing between the pair of guide rails and/or simultaneously adjust a vertical positioning of the pair of guide rails relative to the air conveyor.
(2) Description of the Related Art
Air conveyors are employed in the rapid transport of empty plastic bottles of the type having an annular rim or a neck ring at the base of the bottle neck. A typical air conveyor includes a pair of flanges that are spaced from each other defining an elongated slot between the flanges. The spacing between the flanges is sufficiently large to enable a portion of the bottle just below the neck ring to pass through the spacing with the bottle suspended from the top surfaces of the flanges by the neck ring engaging over the top surfaces. A series of air ducts are positioned along the flanges above and/or below the elongated slot. A plenum of the air conveyor supplies a flow of air to the air ducts. The air ducts are oriented so that the air ejected from the ducts will contact the plastic bottles pushing the bottles along the pathway defined by the elongated slot with the neck ring of the bottles sliding along the top surfaces of the spaced flanges.
Preferably, air conveyors transport bottles in closely spaced succession and at a substantial speed. A typical air conveyor is constructed with both straight sections and curved sections in order to transport the succession of bottles from one area to another. Air conveyors often have guide rails positioned below the slot defined by the pair of flanges. Pairs of guide rails positioned on opposite sides of the slot follow the conveyor path defined by the slot. The guide rails are usually spaced further apart from each other than are the flanges to allow the width of a bottle suspended from the flanges to pass easily between the guide rails. The guide rails limit the side-to-side movement of the succession of bottles conveyed by the air conveyor and thereby limit the extent to which the body of a bottle can swing outwardly or transversely from the air conveyor path and thereby avoids a bottle neck or neck ring potentially becoming jammed in the air conveyor slot and stopping the succession of conveyed bottles.
The positioning of the pair of guide rails relative to the air conveyor slot is determined by the size and shape of the bottle to be conveyed by the air conveyor. The pair of guide rails are spaced a lateral distance from each other that is slightly larger than the width of the bottle to be conveyed along the longitudinal length of the air conveyor. The guide rails are centered laterally relative to the center of the air conveyor slot so that the spacing of the pair of guide rails from laterally opposite sides of the bottle is substantially equal. In addition, the pair of guide rails are positioned vertically relative to the air conveyor slot so that they are positioned on opposite lateral sides of a portion of the bottle having the bottle""s greatest width.
The pair of guide rails are supported beneath the air conveyor slot by a frame that is either supported on a floor beneath the air conveyor or is suspended from the air conveyor. The pair of guide rails are often supported on the frame by brackets that are adjustably connected to the guide rails and adjustably connected to the frame. For example, the guide rails can be attached by screw threaded fasteners to the brackets where the fasteners can be loosened to enable manual adjustment of the vertical positions of the guide rails relative to the brackets and relative to the air conveyor. The fasteners are then tightened to secure the guide rails in their vertically adjusted positions. In addition, the brackets could be attached by screw threaded fasteners to the frame where the fasteners can be loosened to enable manual adjustments to the lateral spacing between the brackets and the pair of guide rails, and then tightened to secure the brackets and guide rails in their laterally adjusted positions.
However, manually adjusting the lateral spacing between a pair of guide rails and the vertical position of a pair of guide rails relative to an air conveyor involves a significant amount of time. All of the fasteners on all of the brackets along the length of the conveyor must be loosened, the adjustments made, and all the fasteners tightened. The time required for these adjustments is further increased depending on the length of the conveyor system. If the conveyor system is being changed from conveying plastic bottles having a smaller diameter to those having a larger diameter, the lateral spacing between the guide rails must be adjusted to a larger spacing while maintaining the pair of guide rails centered beneath the conveyor slot. These adjustments must be made along the entire length of the air conveyor. Furthermore, if the conveyor is being changed over from conveying bottles having a smaller vertical height to conveying bottles having a larger vertical height, the vertical positions of the guide rails relative to the air conveyor may also need to be adjusted. Again, these adjustments must be made along the entire length of the air conveyor system which could take a considerable amount of time. Still further, in multiple conveyor systems where there are a plurality of air conveyor slots arranged side by side, the adjustments must be made to the pairs of guide rails for each of the conveyor slots, thus multiplying the time required for the adjustments. Making all of these adjustments to the guide rails of the air conveyor system results in a considerable amount of down time of the air conveyor.
The problem of the considerable down time needed to adjustably position guide rails of an air conveyor would be overcome by an apparatus that is capable of simultaneously adjusting the lateral spacing between pairs of guide rails and/or simultaneously adjusting the vertical positions of the guide rails relative to the air conveyor.
The two axis guide rail change over apparatus of the invention can be employed with virtually any type of conveyor system that conveys a succession of articles along a longitudinal conveyor path, where any lateral side-to-side movement of the succession of articles is limited by a pair of longitudinally extending guide rails positioned on laterally opposite sides of the conveyor path. In the operative environment of the guide rail change over apparatus to be described, the apparatus is employed on an air conveyor that transports plastic bottles. The bottles are of a conventional type with each bottle having a neck at its upper end and an annular shoulder below the neck that defines the upper portion of the body of the bottle. An outwardly projecting annular rim or neck ring is positioned below the neck of the bottle and above the bottle shoulder.
The air conveyor with which the guide rail change over apparatus of the invention is described is a multi-channel air conveyor where each channel of the conveyor employs a pair of flanges through which the neck and neck ring of the bottle project. The neck ring rests on top surfaces of the spaced flanges suspending the shoulder and body of the bottle below the flanges. The air conveyor includes a series of air ducts along each channel that direct a supply of air against the bottle causing the bottle to move along the length of the air conveyor with the neck ring of the bottle sliding along the top surfaces of the flanges. Air conveyors of this type are described in the U.S. Patents of Ouellette U.S. Pat. No. 5,437,521, issued Aug. 1, 1995, and U.S. Pat. No. 5,611,647, issued Mar. 18, 1997, both of which are assigned to the assignee of the present invention and incorporated herein by reference.
Air conveyors typically include a frame work that supports the conveyor. They also often include guide rails that are supported from the frame work or suspended from the air conveyor in positions just below the air conveyor slot. The guide rails are provided in pairs that extend along the longitudinal length of the conveyor. A lateral spacing between the pair of guide rails is centered below the spacing between the air conveyor flanges that define the slot. The spacing between the guide rails is slightly larger than the body of the bottles to be conveyed by the air conveyor. The guide rails limit the extent to which the bottles conveyed by the air conveyor can rock side-to-side or transversely to their direction of conveyance.
The two axis guide rail change over apparatus of the invention is designed to enable its simple addition to an existing air conveyor system. The apparatus is designed to be substituted for the guide rails of a prior art air conveyor.
In a similar manner to prior art pairs of guide rails that are arranged end to end along the longitudinal length of an air conveyor, the pairs of two axis adjustable guide rails of the invention may also be arranged end to end along a longitudinal length of an air conveyor. In addition, the pairs of two axis adjustable guide rails may also be employed on multiple channel air conveyors in the same manner as prior art guide rail pairs.
The two axis guide rail change over apparatus is supported on a frame that is attached to a multi-channel air conveyor section and suspended below the air conveyor slots of the conveyor section. The frame supports an adjustment mechanism and the adjustment mechanism supports pairs of guide rails that are positioned beneath and laterally centered relative to the slots of the air conveyor. The adjustment mechanism is capable of laterally adjusting the guide rail pairs relative to each other as well as vertically adjusting the positions of the guide rail pairs relative to the air conveyor slots.
The adjustment mechanism includes two pairs of screw threaded rods that extend horizontally and laterally across the conveyor paths defined by the pairs of guide rails. The two pairs of lateral rods are positioned beneath the guide rails with one pair being positioned adjacent the upstream ends of the guide rails and the other pair positioned adjacent the downstream ends of the guide rails. One rod of each pair has right hand screw threading and one rod of each pair has left hand screw threading. A right hand internally screw threaded block is mounted on the right hand screw threaded rod of each pair of rods and a left hand internally screw threaded block is mounted on the left hand screw threaded rod of each pair of rods. One guide rail of.each pair is secured to the two right hand screw threaded blocks at the opposite upstream and downstream ends of the guide rails and the other guide rail of each pair is secured to the two left hand screw threaded blocks at the opposite upstream and downstream ends of the guide rails.
The two pairs of lateral rods are interconnected by a chain drive system that rotates each of the rods at the same speed and in the same direction of rotation. The chain drive system is selectively driven by either a manual hand crank or an electric gear motor to rotate all of the lateral rods in a first direction of rotation or rotate all of the lateral rods in an opposite, second direction of rotation.
By rotating the rods in either the first or second directions of rotation, due to the right hand and left hand screw threading of the lateral rods of each pair, the blocks mounted on the rods will move laterally toward or away from each other. This, in turn, results in the simultaneous movement of the guide rails of each pair laterally toward and away from each other. By calibrating the number of turns of the manual handle of the chain drive system needed to move the guide rails of each pair a certain distance relative to each other, the lateral spacing between adjacent guide rails of each pair can be quickly adjusted to any desired lateral distance by rotating the handle in the appropriate direction and for the appropriate number of turns. Alternatively, by interconnecting a counter in the train drive system that calibrates the direction and number of rotations of the electric gear motor output shaft needed to adjust the lateral distance between the guide rails of each pair, the lateral spacing between the guide rails of each pair can be quickly adjusted to a desired lateral spacing.
The pairs of transverse threaded rods are received in bearing journals at their opposite ends that, in turn, are mounted on pairs of channel members. The channel members extend the longitudinal length of the conveyor section and are positioned on laterally opposite sides of the pairs of guide rails. Each of the channel members has an internally screw threaded block at its opposite upstream and downstream ends. Each of the four screw threaded blocks is mounted on one of four vertical screw threaded rods with the four blocks and the two channel members being positioned in the same horizontal plane.
The four vertical rods are interconnected by a chain drive system that drives each of the four rods at the same speed in opposite first and second directions of rotation. The chain drive system of the vertical rods is powered by a manual hand crank or an electric gear motor. The rotation of the vertical rods in opposite directions of rotation causes the four internally screw threaded blocks and the attached pair of channel members to move together vertically upwardly and downwardly relative to the air conveyor. This, in turn, causes the pairs of guide rails supported on the lateral rods, which are supported between the two longitudinal channel members, to move vertically upwardly and downwardly relative to the air conveyor channels.
As in the chain drive system for the transverse rods, the direction and number of rotations of the hand crank can be calibrated to adjustably position the pairs of guide rails at a desired vertical position relative to the air conveyor channels. Alternatively, with the transverse rods having a standard ACME thread of six threads per inch, counters are commercially available that count 0.1667 inches per revolution (or one inch per six revolutions). Such a counter can be interconnected with the chain drive system of the vertical rods to determine the direction and extent of output shaft movement needed to adjustably position the pairs of guide rails at a desired vertical position relative to the air conveyor channels.
The two axis guide rail change over apparatus of the invention provides a means of quickly and simultaneously adjusting the lateral spacing between adjacent pairs of guide rails and/or adjusting the vertical position of the pairs of guide rails relative to an air conveyor. The apparatus is equally well-suited for use with multiple channel conveyors as well as single channel conveyors.